160 CIVIC BIOLOGY 



possible and that it will be only a question of a few years " ; 

 but now, nearly fifteen years later, it is still gaining ground. 



Since a large portion of the year is passed in the egg stage, 

 this is the natural time for extermination. The egg masses 

 are conspicuous dark yellow splotches, and in a badly infested 

 region may be found anywhere, on fence or stone wall, 

 under porches, among dead leaves, although the first and 

 most common position is the trunk and branches of trees. The 

 rapid fire which is sometimes sent through woods and under- 

 brush to destroy other pests has no marked effect on these 

 eggs. Attempts to remove the egg masses by scraping have 

 proved equally ineffective, for eggs become scattered in the 

 process and hatch as readily as ever. 



Saturating the egg clusters with the following mixture : 

 creosote oil 50 per cent, carbolic acid 20 per cent, spirits of 

 turpentine 20 per cent, coal tar 10 per cent, is the method of 

 extermination recommended by state authorities. It is applied 

 with a small brush. This treatment must find every egg mass, 

 and therefore must be begun the instant the presence of the 

 insect is known. The insatiable appetite of caterpillars makes 

 so omnivorous a creature as the gypsy moth even more dreaded, 

 for when one feeding ground is exhausted, a fresh one over the 

 fence or across the road is quickly attacked. Thus the pest 

 moves on, leaving every twig stripped behind it. 



Every effort must be made to keep- the pest within its pres- 

 ent limits. The female imago does not fly ; therefore distri- 

 bution is effected by the caterpillars which frequently spin 

 down from the trees and fall upon passing conveyances, or by 

 egg masses which are overlooked on lumber or are carried in 

 various ways. 



Brown-tail moth. The problem of the brown-tail moth is 

 one of even greater importance to the country at large be- 

 cause of the greater rapidity of distribution. Both male and 

 female are strong, swift flyers, and eggs may be deposited at 



